Problem when cropping image on overlay locator

Hi Asko,

I have a problem when cropping on overlay.
The cropping area is shifted under the given locator.

You can reproduce the problem with the following script.
[test.robot.txt](https://github.com/datakurre/robotframework-selenium2screenshots/files/2148508/test.robot.txt)

Thanks in advance
Regards
Stephan

Start by downloading and running the attached test.robot.txt reproduction script. Trace the cropping behavior for an overlay locator and determine where the crop area becomes shifted beneath the locator. Done means the reproduced crop area aligns with the given locator without breaking the existing screenshot behavior.

Written by the indexing model from the issue text.